Add neutral administrator lobby configuration

Configure supported rules/modules and AI seats or assign an existing human as host without granting private-seat access. Use genuine unused-lobby checks, existing engine actions, live authorization/version/pause/seat fences and atomic audit receipts. Preserve exact account-bound retries across refresh and confirm completed operations after game start without resetting play.

Verified types, lint, 5260 offline tests, 52 HTTP tests and build. Eleven authenticated HTTP groups and independent privacy/persistence review passed. Browser QA confirmed one AI and audit after a lost response and refresh/retry, persisted rules and AI configuration, and readable 1280/390px layouts. All existing rooms and seats preserved. Actual authenticated production administrator acceptance remains pending authorized QA operator access.

docs/ADMIN_ROOM_CREATION.md

@@ -14,9 +14,9 @@ set up for another person, use the existing **Pass your seat to another player**
 flow in that lobby; the host player identity and room progress survive transfer.
 This workflow grants no access to any existing participant's seat.
 
-This is a connected room-creation prototype, not complete neutral administrator
-lobby management. Creating reserved human seats, assigning a different existing
-participant as host and managing lobbies without a playing seat remain part of
+Use [Configure lobby](ADMIN_LOBBY_CONFIGURATION.md) to manage rules and AI seats
+or assign another existing human as host without a playing seat. Reserved human
+seats and remaining administration still belong to
 [the full panel requirements](ADMIN_PANEL.md).
 
 ## Saved confirmation